Leakage of the Inner Water Phase into the Outer Water Phase in W/O/ W Emulsion

Abstract

Mixing between the inner and outer water phases in W/O/W emulsion was measured by means of a radioactive tracer under conditions excluding the effect of electrolytes in the water phases. The leakage fraction was proportional to the square of the agitating speed and inversely proportional to the 0.7 power of the concentration of the surfactant Span80^®. The leakage fraction increased as the volume fraction of the inner water phase inside the dispersed W/O emulsion droplets increased. The volume fraction of the W/O emulsion droplet in the W/O/W emulsion system had no effect on the leakage fraction. When hydrochloric acid was added to the inner water phase at small surfactant concentration, the leakage fraction was larger than the value for the system without electrolytes. When surfactant concentration was large, the leakage fraction did not increase even if hydrochloric acid was added to the inner water phase. The dependence on the agitating speed was the same as that for the system without electrolytes.